1. Technical Field
The present invention relates generally to an improved truck assembly for skateboards and street luges and more particularly to provide speed and fast reaction maneuverability.
2. Background Art
Skateboards have gained wide acceptance for recreational and sport activities. Competitions in skateboards have included downhill skateboard racing and slalom courses. Since the participants travel at relatively high speeds and require quick maneuverability in turns, the performance of the truck assembly is important. Additionally, such truck assemblies can also be utilized in street luges.
A prior art skateboard and trucks are shown in FIGS. 11 through 14. FIG. 11 is a perspective view that shows an assembled skateboard. FIG. 12 is a front view of a prior art truck. FIG. 13 is a side view of the prior art truck. FIG. 14 is an expanded cross-sectional view of a prior art truck with a skateboard attached.
Generally, a skateboard comprises a board 1 and a set of wheels 2 that are attached to a bottom surface of the board 1. The wheels 2 are attached to the board using trucks 3. A truck 3 is mounted to the bottom surface of the board 1 by a mounting base 21 that comprises a socket hub 15 and a bracket 13. The mounting base 21 is generally mounted to the board 1 by bolts and nuts at mounting holes 17. The truck 3 comprises a right and left wheel axle 4 that extend perpendicularly to a side of the board 1 and the direction of the skateboard""s travel. Each wheel axle 4 is mounted through a yoke 6 and affixed with an axle nut 5.
The yoke 6 comprises a pivot arm 14 that is connected to the mounting base 21 at the socket hub 15. The pivot arm 14 is inserted into a rubber bushing mount 16, usually urethane, in a pivot hole 15a in the socket hub 15.
The connection of the pivot arm 14 to the mounting base 21 at the socket hub 15 by using the rubber bushing 16 is usually done to reduce damage to the board 1 from vibration and positional change from any up and down motion of the yoke 6 during use. However, in a prior art truck, significant frictional forces can occur between the pivot arm 14 and the rubber busing 16 and between the pivot hole 15a and the rubber busing 16 when the board 1 inclines right or left during maneuvering, and in particular during slalom riding. The pivot arm 14 of the prior art skateboard truck may not rotate smoothly and therefore can reduce maneuverability.
The yoke 6 further comprises a hanger 7 that is flexibly clamped by an upper grommet 8 and a lower grommet 9. A king bolt 10 passes through the lower grommet 9, the hanger 7 and the upper grommet 8 at the bolt holes 9a, 7a and 8a respectively and into the bracket 13 at bolt hole 13a. The king bolt 10 is affixed by a nut 11 and washer 12.
The upper grommet 8 is generally shaped as a large, thick circular pillar. Though this structure absorbs impact, it may cause the wheel axle 4 to resist right or left movements when the user shifts his/her weight and may further reduce operating performance by hindering rotation of the wheel axle 4.
Thus, an improved skateboard truck is needed that allows for smoother pivot arm rotation associated with the right or left incline of the skateboard and increased operating performance of the wheel axis during such maneuvers.
The present invention relates generally to an improved skateboard truck for skateboards and luges. The preferred skateboard truck comprises a yoke mounted by a king bolt to a mounting base. The mounting base comprises a socket hub and a bracket. The yoke comprises a hanger and a pivot arm. The pivot arm can rotate freely in a ball bearing unit that supports the pivot arm in the socket hub. The king bolt clamps the hanger between a first grommet and a second grommet. The first grommet is flexible, preferably made of urethane rubber, and can comprise an edge circumference and a center circumference. The center circumference is narrower than the edge circumference. Preferably, the first and second grommets are fluorescent.